respiration

Question 1

the process of glycolysis

Answer 1

.two ATP donate phosphate groups to glucose forming hexose biphosphate
.hexose biphosphate is split into two triose phosphate(TP)
. a another phosphate group is added to each TP turning them into triose biphosphate
.hydrogen is removed from each triose biphosphate and used to form reduced NAD, 2 pyruvate and 4 ATP

Question 2

why is glycolysis a anaerobic process

Answer 2

as it does not require oxygen

Question 3

what is substrate level phosphorylation

Answer 3

.formation of ATP without the involvement of an electron transport chain

Question 4

what is the net gain for glycolysis

Answer 4

2 ATP and 2 reduced NADP

Question 5

link reaction process

Answer 5

.pyruvate from glycolysis is actively transported into the matrix of mitochondria via carrier proteins
.each pyruvate is decarboxylated losing a CO2 group
.CO2 diffuses out of the mitochondria as waste product
.two hydrogen groups are removed from pyruvate to form acetate
.the hydrogen is used to reduce NAD into reduced NAD
.acetate binds to coenzyme A forming CoA

Question 6

Krebs cycle process

Answer 6

.CoA merges with a oxaloacetate molecule to form a citrate molecule
.citrate is decarboxylated releasing two CO2
.citrate is dehydrogenated to reduce 3 NAD and 1 FAD
.each CoA that enters the cycle = one ATP is synthesised(in substrate level phosphorylation)
.oxaloacetate is regenerated for the next turn of the cycle

Question 7

differences between NAD and FAD

Answer 7

NAD accepts 1 electron and proton but FAD accepts 2 electron and protons

NAD is in all stages of respiration but FAD is only in the Krebs cycle

NAD synthesises 3 ATP but FAD only synthesises 2 ATP

Question 8

where does oxidative phosphorylation occur

Answer 8

inner fold of the mitochondria

Question 9

oxidative phosphorylation process

Answer 9

.reduced NAD and FAD release hydrogen into the mitochondrial matrix
.high energy electrons are passed to an electron carrier from reduced NAD and FAD
.electrons are passed along a series of electron carriers in the electron transport chain releasing energy
.the energy is used to actively transport protons across the inner mitochondrial matrix into the intermembrane space
.the accumulation of protons in the intermembrane space causes a steep electrochemical gradient of protons
.protons diffuse back into the mitochondrial matrix down the electrochemical gradient through ATP synthase
.this releases energy and catalyses the synthesis of ATP to ADP and Pi
.oxygen combines with electrons and protons to form water maintaining the proton gradient

Question 10

what is chemiosmosis

Answer 10

diffusion of protons across the partially permeable inner membrane down the electrochemical gradient via ATP synthase channels

Question 11

what is the net gain of ATP for aerobic respiration

Answer 11

.glycolysis = 2 (2 used)
.link = 0
.Krebs = 2
.Oxidative phosphorylation = 30
total 34

Question 12

differences of aerobic and anaerobic respiration

Answer 12

.aerobic occurs in the cyto and mito but anaerobic occurs only in the cyto

.aerobic contains the whole process whereas anaerobic only contains glycolysis

.aerobic yields 34 ATP per glucose molecule while anaerobic only yields 2 ATP

Question 13

what are obligate anaerobes

Answer 13

cannot survive in presence of oxygen

Question 14

what are facultative organisms

Answer 14

can switch between aerobic and anaerobic

Question 15

what are obligate aerobes

Answer 15

depend on oxygen to synthesise ATP

Question 16

alcohol fermentation

Answer 16

.in yeasts and some plants
.pyruvates loses a CO2 and is converted into ethanal
.ethanal accepts a hydrogen from reduced NAD forming ethanol and regenerates NAD
.Ethanol is removes as waste product

Question 17

how can lipids be used as respiratory substrates

Answer 17

.by being hydrolysed into glycerol and fatty acids
.glycerol is converted into triose phosphate
.fatty acids are broken down into two carbon fragments and converted into CoA to enter the Krebs cycle

Question 18

how can proteins be used as respiratory substrates

Answer 18

.hydrolysed into amino acids
.amine group is removed and the 3 carbon compound is converted into pyruvate
.4 and 5 carbon compounds are converted into intermediates in the Krebs cycle

Question 19

what is the respiratory quotient

Answer 19

ratio of the volume of CO2 produced to the volume of O2 used during respiration

RQ = vol of CO2 produced/vol of O2 consumed

Question 20

what are the RQ values of the respiratory substrates

Answer 20

Carbs = 1
lipids = 0.7
proteins = 0.9

more than 1 = anaerobic respiration

.low RQ = photosynthesis